Block Carton

ABSTRACT

A first surface and a second surface, wherein said first surface comprises a plurality of evenly distributed surface protrusions that correspond to cavities on the second surface, a rectangular lid face, and a rectangular bottom face which is connected to two opposed long side panels and two opposed short side panels and wherein the lid face and the bottom face are connected to each other via a side panel which is secured to a side edge on the bottom face and the lid face, respectively, wherein the lid face comprises one or more lid panels along the remaining side edges of the lid face, and wherein the side panels preferably comprise corner flaps arranged in correspondence with the corners of the bottom panel. Hereby a number of advantages are obtained from a production point of view, since a block carton is provided that enables even adhesion of the food substance to the block carton, said block carton exhibiting a larger surface than the prior art block cartons.

The present invention relates to a block carton as featured in the preamble to claim 1.

Today, block cartons are used eg within the fishing industry to pack fresh foodstuffs in blocks prior to a freezing procedure. Typically a block carton is made in the form of a plane cover with pre-embossed folding lines. Such block carton is known in the industry ia by the designation “fishblock-liner” or “blanket”.

Typically a block carton consists of a rectangular bottom face and a rectangular lid face, each of which has two opposed long side panels and two opposed short side panels, and wherein the lid face and the bottom face are connected to each other via a side panel which is secured to a side edge of the bottom face and the lid face, respectively. The lid face may be provided with one or more lid panels along the remaining side edges of the lid face. In order to ensure improved closure of the carton when being erected (folded) in a freezing frame, the side panels may be provided with corner flaps secured to one single side panel and extending from the side of the side panel. Such closure of the corners protects against liquid seeping from the erected block carton, and likewise the contents are protected against damage (freeze burn) during the subsequent freezing procedure. The various panels are preferably connected to each other corresponding to the above-mentioned pre-embossed folding lines.

Typically, the block carton is manufactured from cardboard or paperboard and is coated with a coating arranged on the inside and serving to control the absorption of liquid going on between the unfrozen food substance and the board material of the block carton. To control such absorption of liquid, it is thus known to also coat the inside of the block carton with paraffin and moreover to provide the inside of the block carton with a large number of small openings, the so-called “pinholes”: The number and location of such pinholes are determined with due regard to the construction of the block carton and the food substance to be frozen. It is desirable precisely that a certain amount of liquid is absorbed by the board material, since it has been found to be advantageous that a certain adhesion of the food substance to the block carton occurs, such adhesion contributing to a more durable packaging of the food substance.

Precisely the absorption of liquid through the so-called “pinholes” has, in some cases, involved that, during the freezing procedure, locally the block carton freezes and bonds to the food substance, which is inconvenient. However, it is a problem in this context that ice formations occur at the transition between food substance and block carton, and that a subsequent processing of the frozen food substance is made difficult due to the local freeze bonding.

It is therefore the object of the invention to provide a block carton by which the problems associated with the prior art are obviated and by which a more rational and flexible production is obtained.

This is obtained by the invention according to the characterising part of claim 1. Hereby a number of advantages are obtained from a production point of view, since a block carton is provided that enables an even adhesion of the food substance to the block carton, said block carton exhibiting a larger surface than the known block cartons. Moreover, the surface protrusions mean that the food substance will stick to both the tips of the surface protrusions and to the cavity in adjoining oppositely oriented surface protrusions. At the same time the particular configuration of the surface protrusions ensures an adhesion which is able to absorb forces perpendicular to the surface of the block carton, which contributes to a more durable packaging of the food substance.

As mentioned above, it is essential that the outer surface of the packaging is made essentially impenetrable to water vapour/liquid, meaning in practice that a permeability value of less than 20 g/m² at 23° C. and a relative humidity of air of 50%, preferably less than 10 g/m², is concerned.

The invention will now be described in further detail with reference to the drawing, wherein

FIG. 1 is a perspective view, seen from above, of the interior side of a non-folded cover for a first block carton 1.

Thus, FIG. 1 shows a block carton 1 in non-folded state. The block carton 1 is preferably made of cardboard and configured to be particularly suitable in the context of freezing fish or fish substance. The block carton 1 comprises two surfaces 11, 12 and on both sides 11, 12, ie on both the inner side and the outer side, it is provided with a plurality of evenly distributed, elongate surface protrusions that will be subject to more detailed description below.

The block carton 1 is constituted by a rectangular bottom face 2 being, along two opposite side edges 13, connected to each long side panel 5. The bottom face 2 is moreover connected to two opposed short side panels 6. The one of said long side panels 5 is in turn connected to a rectangular lid panel 3, being, along its short side edges 14 and at its free long side edge 15, connected to lid panels 4.

All of the above-mentioned elements are connected to each other corresponding to pre-embossed folding lines or so-called cardboard bridges 13, 14, 15, indicated by dotted lines in the FIGURE. Said folding lines/cardboard bridges 13, 14, 15 provide a higher degree of certainty that the block carton 1 is folded correctly in the folding process; and that hence the block carton will fit into a freezing frame and fill it completely. The side panels 6 are provided with corner flaps that are secured to one single side panel and extend from the side of the side panel.

The two sides (surfaces) 11, 112 of the block carton are intended for forming the inner and outer sides, respectively, of the folded block carton and are configured with a number of surface protrusions/bulges 21 that extend from alternatingly the one and the other, respectively, of surfaces 11, 12.

Preferably the surface protrusions 21 are frustoconical and extend alternatingly from the outer side 12 in a direction towards the inner side; and from the inner side 11 in a direction towards the outer side 12. Therefore, it will be understood in this respect that the surface protrusions 21 extend alternatingly from one surface and the other. In this context, it will be understood that a surface protrusion 21 extending from the outside 12 will also bring about an elevation on the opposite side, ie the inner side 11, and vice versa, whereby a crepped surface is obtained. Each of the surfaces is configured with from two to fifteen surface protrusions 21 per cm², and preferably with four surface protrusions 21 per cm².

Preferably each of surfaces 11, 12 on the block carton 1 is provided with elongate surface protrusions 21 that are further oriented in the same direction. However, the person skilled in the art will be able to point to other advantageous manners in which to orient the surface protrusions 21, including to configure them at an angle relative to each other and, likewise, a combination of circular and elongate surface protrusions will be an option.

The one surface is preferably coated with a coating in the form of paraffin, wax, a plastics coating or varnish in water-insoluble form, and the other surface will preferably be coated with either a coating in the form of a varnish in a water-insoluble form, wax or a paraffin.

As described above the external coating on a block carton primarily provides a sealing of the surface in order to thereby make it essentially impermeable to water vapour and liquid. Conversely, the interior coating may be configured with a view to either allowing a controlled uptake of liquid from the contained food substance, or it may be configured to be essentially impermeable to water vapour and liquid in response to the particular conditions that prevail for the foodstuff to be frozen. This is advantageously provided by varying the thickness of the coating on the inner side of the block carton.

In particular cases, eg when quite particular requirements are made to the degree of adhesion, it may be expedient to coat the inner side of the block carton with a wax or paraffin coating; it being noted, however, that otherwise a varnish coat or a plastics coat would be the preferred choice.

It will be understood that the FIGURE is merely schematic and not to scale and that only details essential to the understanding of the invention are shown, while other details are omitted for the sake of clarity. In all FIGURES the same reference numerals are used for identical or corresponding parts. 

1. A block carton, comprising: a first surface and a second surface, wherein said first surface comprises a plurality of evenly distributed surface protrusions that correspond to cavities on the second surface, a rectangular lid face, and a rectangular bottom face that are connected to two opposed long side panels and two opposed short side panels, and wherein the lid face and the bottom face are connected to each other via a side panel which is secured to a side edge on the bottom face and the lid face, respectively, wherein the lid face comprises one or more lid panels along the remaining side edges of the lid face, and wherein the side panels preferably comprise corner flaps arranged in correspondence with the corners of the bottom panel, wherein the second surface comprises a plurality of evenly distributed surface protrusions that correspond to cavities on the first surface, whereby a crepped surface is accomplished.
 2. A block carton according to claim 1, wherein the surface protrusions extend from alternatingly the first and the second surfaces.
 3. A block carton according to claim 1, wherein at least one of the surfaces comprises elongate surface protrusions; and that said elongate surface protrusions are oriented essentially in the same direction.
 4. A block carton according to claim 1, wherein said elongate surface protrusions are oriented at an angle relative to each other.
 5. A block carton according to claim 1, wherein at least one of the surfaces is coated with a varnish in a water-insoluble form.
 6. A block carton according to claim 1, wherein the first coating is in the form of a varnish in a water-insoluble form; and wherein the second coating is a paraffin coating.
 7. A block carton according to claim 1, wherein the first and the second coatings are in the form of a varnish in a water-insoluble form.
 8. A block carton according to claim 1, wherein the first coating is thicker than the second coating.
 9. A block carton according to claim 1, wherein each of the surfaces is configured with from two to 15 surface protrusions per cm², and preferably four surface protrusions per cm².
 10. A block carton according to claim 1, wherein the varnish is selected from among the group comprising water-soluble and settable/set varnishes. 